[LTP] [PATCH] Introduce ioctl_pidfd_get_info_supported() function

[Avinesh Kumar]

- use new routine in ioctl_pidfd05 test
- refactor ioctl_pidfd_info_exit_supported() routine

Suggested-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Avinesh Kumar <akumar@suse.de>
---
 testcases/kernel/syscalls/ioctl/ioctl_pidfd.h | 45 +++++++++++--------
 .../kernel/syscalls/ioctl/ioctl_pidfd05.c     |  9 +++-
 2 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/testcases/kernel/syscalls/ioctl/ioctl_pidfd.h b/testcases/kernel/syscalls/ioctl/ioctl_pidfd.h
index 811f969cd..6ee6c6db5 100644
--- a/testcases/kernel/syscalls/ioctl/ioctl_pidfd.h
+++ b/testcases/kernel/syscalls/ioctl/ioctl_pidfd.h
@@ -9,19 +9,16 @@
 #include "tst_test.h"
 #include "lapi/pidfd.h"
 
-static inline int ioctl_pidfd_info_exit_supported(void)
+static inline long ioctl_pidfd_get_info_supported(void)
 {
-	int ret;
 	pid_t pid;
-	int pidfd;
-	int supported = 0;
+	int pidfd, ret;
 	struct pidfd_info info;
 
-	if (tst_kvercmp(6, 15, 0) >= 0)
+	if (tst_kvercmp(6, 12, 0) >= 0)
 		return 1;
 
 	memset(&info, 0, sizeof(struct pidfd_info));
-	info.mask = PIDFD_INFO_EXIT;
 
 	pid = SAFE_FORK();
 	if (!pid)
@@ -31,23 +28,33 @@ static inline int ioctl_pidfd_info_exit_supported(void)
 	SAFE_WAITPID(pid, NULL, 0);
 
 	ret = ioctl(pidfd, PIDFD_GET_INFO, &info);
+	SAFE_CLOSE(pidfd);
+
 	if (ret == -1) {
-		/* - ENOTTY: old kernels not implementing fs/pidfs.c:pidfd_ioctl
-		 * - EINVAL: until v6.13 kernel
-		 * - ESRCH: all kernels between v6.13 and v6.15
-		 */
-		if (errno != ENOTTY &&
-			errno != EINVAL &&
-			errno != ESRCH)
-			tst_brk(TBROK | TERRNO, "ioctl error");
-	} else {
-		if (info.mask & PIDFD_INFO_EXIT)
-			supported = 1;
+		if (errno == ENOTTY)
+			return -1;
+
+		if (errno == EINVAL || errno == ESRCH)
+			return 0;
+
+		tst_brk(TBROK | TERRNO, "unexpected ioctl(PIDFD_GET_INFO) error");
 	}
 
-	SAFE_CLOSE(pidfd);
+	return info.mask;
+}
+
+static inline int ioctl_pidfd_info_exit_supported(void)
+{
+	long mask;
+
+	if (tst_kvercmp(6, 15, 0) >= 0)
+		return 1;
+
+	mask = ioctl_pidfd_get_info_supported();
+	if (mask == -1)
+		return 0;
 
-	return supported;
+	return !!(mask & PIDFD_INFO_EXIT);
 }
 
 #endif
diff --git a/testcases/kernel/syscalls/ioctl/ioctl_pidfd05.c b/testcases/kernel/syscalls/ioctl/ioctl_pidfd05.c
index c379717b3..871f2fe5e 100644
--- a/testcases/kernel/syscalls/ioctl/ioctl_pidfd05.c
+++ b/testcases/kernel/syscalls/ioctl/ioctl_pidfd05.c
@@ -14,7 +14,7 @@
 #include "tst_test.h"
 #include "lapi/pidfd.h"
 #include "lapi/sched.h"
-#include "lapi/ioctl.h"
+#include "ioctl_pidfd.h"
 
 struct pidfd_info_invalid {
 	uint32_t dummy;
@@ -48,8 +48,15 @@ static void run(void)
 	SAFE_CLOSE(pidfd);
 }
 
+static void setup(void)
+{
+	if (ioctl_pidfd_get_info_supported() == -1)
+		tst_brk(TCONF, "ioctl(PIDFD_GET_INFO) is not implemented");
+}
+
 static struct tst_test test = {
 	.test_all = run,
+	.setup = setup,
 	.forks_child = 1,
 	.bufs = (struct tst_buffers []) {
 		{&args, .size = sizeof(*args)},
-- 
2.51.0